The poly(oxyalkylene)acrylamides are obtainable by various routes. The chemical synthesis of poly(oxyalkylene)acrylamides is effected by direct esterification or transesterification of acrylic acid or acrylic esters with poly(oxyalkylene)amines and proceeds at temperatures of above 100° C. under acid catalysis (DE 3130508 Röhm GmbH 1981).
Owing to the high temperatures, the addition of large amounts of polymerization inhibitors is necessary. As a result of the high reaction temperatures, Michael adducts of the amine to the double bond of the acrylic acid compound form. Complex and often dark product mixtures with troublesome odor are formed. The reaction of acryloyl chloride with amines likewise affords N-alkylacrylamides. However, the process is not economically viable owing to the high costs of acryloyl chloride.
The biocatalytic synthesis of acrylamides is described in the documents which follow. Puertas et al. (Tetrahedron 1993, 49, 4007-4014) describe the reaction of methyl (meth)acrylate with butylamine, benzylamine, 2-aminobutane and 2-aminoheptane. The lipase-catalyzed syntheses gave rise to yields of 40-95% within 3-10 days.
Sanchez et al. (Synlett 1994, 529-530) describe the ammonolysis of methyl(meth)acrylate with ammonia to give (meth)acrylamide. The lipase-catalyzed reaction afforded up to 91% yield after 93 h.
Margolin et al. (J. Am. Chem. Soc. 1991, 113, 4693-4694) describe the reaction of trifluoroethyl methacrylate with 1-(1-naphtyl)ethylamine or phenylalaninamide. The reaction was catalyzed by the protease subtilisin.
Egraz et al. (U.S. Pat. No. 5,973,203) claim the enzymatic synthesis of (meth)acrylamides comprising tertiary amino groups. In this synthesis, an alkyl(meth)acrylate reacts with a diamine which has one primary and one tertiary amino group.